320 



VETERINARY MEDICINE AND SURGERY. 



The various changes which take place in the i^osition of the teeth in 

 reference to their position or " slope " are shown in Figs. 162 to 167. At 

 two years old (Fig. 164) the gums are full, fleshy and prominent, and the 

 teeth are nearly perpendicular. The gradual changes which take place 

 in the slojje with increasing years are shown perhaps more clearly in the 

 engravings than could be explained in words. 



Up to twelve years old, there can scarcely be much diflScuIty in form- 

 ing a pretty correct judgment as to the age. After that time it requires 

 more time, practice and opportunity than most people have at disposal or 

 care to take to obtain the requisite knowledge. 



It would probably scarcely interest one not a professional veterinarian, 

 to trace very minutely the changes which take place after twelve years 

 old. Suffice it to say, that the gums continue year by year to recede, the 

 teeth become apparently longer and longer and really narrower, and con- 

 sequently the intervals between them increase, and they project forward 

 more and more in a straight line. 



Fig. 1(56. 

 Slope of Teeth at Twelve Years. 



Fi3. 167. 

 Slope of Teeth at Eighteen Years. 



About twenty or twenty-two, and in some instances a good de 

 sooner, the teeth, which up to this period have apparently increased in 

 length, begin to grow visibly shorter, because the gums are so far ab- 

 sorbed that they can recede no further. Hence all further wear shows 

 its effects by diminishing the length of the teeth. 



Loss of Circularity.— In the very young horse the teeth are arranged 

 almost in the form of a semicircle. Year by year this form decreases, 

 until in old horses the teeth are arranged in something like a straight 

 line. Compare Figs. 138, 139, 140, 141, and 143 with Figs. 158, 159, 

 160, and 161. 



These drawings of the teeth have all been made from nature; and 

 hence, although pretty normal specimens have been selected, yet in vari- 

 ous ways they present in some instances irregularities and deviations from 



